Re: [PATCH v2 2/3] ceph: add missing cpu_to_le32() calls when encoding a reconnect capability

[Alex Elder <elder@inktank.com>]

On 05/15/2013 11:38 AM, Jim Schutt wrote:
> In his review, Alex Elder mentioned that he hadn't checked that num_fcntl_locks
> and num_flock_locks were properly decoded on the server side, from a le32
> over-the-wire type to a cpu type.  I checked, and AFAICS it is done; those
> interested can consult Locker::_do_cap_update() in src/mds/Locker.cc and
> src/include/encoding.h in the Ceph server code (git://github.com/ceph/ceph).
> 
> I also checked the server side for flock_len decoding, and I believe that
> also happens correctly, by virtue of having been declared __le32 in
> struct ceph_mds_cap_reconnect, in src/include/ceph_fs.h.
> 
> Signed-off-by: Jim Schutt <jaschut@sandia.gov>

Looks good, but I'd like to get someone else to confirm
the other end is doing it right (i.e., expecting little
endian values).

Reviewed-by: Alex Elder <elder@inktank.com>

> ---
>  fs/ceph/locks.c      |    7 +++++--
>  fs/ceph/mds_client.c |    2 +-
>  2 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c
> index ffc86cb..4518313 100644
> --- a/fs/ceph/locks.c
> +++ b/fs/ceph/locks.c
> @@ -206,10 +206,12 @@ int ceph_encode_locks(struct inode *inode, struct ceph_pagelist *pagelist,
>  	int err = 0;
>  	int seen_fcntl = 0;
>  	int seen_flock = 0;
> +	__le32 nlocks;
>  
>  	dout("encoding %d flock and %d fcntl locks", num_flock_locks,
>  	     num_fcntl_locks);
> -	err = ceph_pagelist_append(pagelist, &num_fcntl_locks, sizeof(u32));
> +	nlocks = cpu_to_le32(num_fcntl_locks);
> +	err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
>  	if (err)
>  		goto fail;
>  	for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
> @@ -229,7 +231,8 @@ int ceph_encode_locks(struct inode *inode, struct ceph_pagelist *pagelist,
>  			goto fail;
>  	}
>  
> -	err = ceph_pagelist_append(pagelist, &num_flock_locks, sizeof(u32));
> +	nlocks = cpu_to_le32(num_flock_locks);
> +	err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
>  	if (err)
>  		goto fail;
>  	for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> index 4f22671..d9ca152 100644
> --- a/fs/ceph/mds_client.c
> +++ b/fs/ceph/mds_client.c
> @@ -2485,7 +2485,7 @@ static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
>  			lock_flocks();
>  			ceph_count_locks(inode, &num_fcntl_locks,
>  					 &num_flock_locks);
> -			rec.v2.flock_len = (2*sizeof(u32) +
> +			rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
>  					    (num_fcntl_locks+num_flock_locks) *
>  					    sizeof(struct ceph_filelock));
>  			unlock_flocks();
>